气态甲醛的二氧化钛光催化氧化：原位红外光谱研究[外文翻译].zip

材料科学与工程 材料物理与化学，外文文献翻译及原文

Photocatalytic Oxidation of Gaseous Formaldehyde on TiO2:An In Situ DRIFTS Study

气态甲醛的二氧化钛光催化氧化：原位红外光谱研究

Abstract The adsorption and photocatalytic oxidation offormaldehyde on the pure TiO2under dry and humidconditions were studied by in situ diffuse reflectanceFourier transform infrared spectroscopy. It was found thatthe formaldehyde molecules can be adsorbed on thehydroxyl groups on the TiO2surface via hydrogen bonding.With UV irradiation, the adsorbed formaldehyde rapidlyconverts to the formate species even on the pure TiO2atroom temperature and atmospheric pressure. In the dryenvironment, the superoxide radical anion O2- , formed byadsorbed oxygen reacting with electrons, is suggested toplay an important role in the formaldehyde oxidation. Theintroduction of water vapor provides a large amount ofwater and hydroxyl groups on the catalyst surface. Oxi-dation of water and hydroxyl groups by the photogeneratedholes produces very active OH radicals, which take part inthe redox reactions and improve significantly the mineral-ization rate of formaldehyde on the TiO2due to its highredox potential.

在干燥和潮湿的的条件下，通过原位漫反射傅里叶变换红外光谱，对吸附在纯TiO2上的甲醛进行光催化氧化研究。结果发现，甲醛分子可以通过氢键被吸附在在TiO2表面的羟基上。在紫外光照射下，即使是在纯TiO2在室温大气压力下，被吸附的甲醛可以迅速转换为甲酸盐。在干燥的环境下，由吸附的氧与电子反应形成的超氧阴离子自由基O2-•，被认为在甲醛氧化方面发挥重要作用。水蒸汽的引入在催化剂表面上提供了大量的水和羟基。水和羟基基团的氧化，由光生的孔穴产生非常活泼的-OH自由基，这种-OH自由基由于其高氧化还原性，可以参与氧化还原反应，并显著改善二氧化钛矿化的甲醛率。